Estimation of valsartan and hydrochlorothiazide in pharmaceutical dosage forms by absorption ratio method.

ABSTRACT

A new absorption ratio method was developed and validated for the determination of valsartan and hydrochlorothiazide in tablets. Calibration curves for valsartan and hydrochlorothiazide over concentration range of 2-20 μg/ml were plotted and molar absorptivity for both the drugs were calculated at both the wavelengths of 270.5 nm (l-max of hydrochlorothiazide) and 231.5 nm (iso- absorptive point). The results of analysis have been validated statistically and by recovery studies. The value of standard deviation was satisfactory and recovery studies ranging from 99.05-102.23% for valsartan and 97.42-100.22% for hydrochlorothiazide were indicative of the accuracy and precision of the proposed method. The results of the assay are in good agreement with the label amount. The method was found to be simple, rapid, and accurate and can be adopted in routine analysis of these drugs in formulations. Due to these attributes, the proposed method could be used for routine analysis of these drugs in combined dosage forms.